The present invention relates to a novel cannula injection device for permitting access to a liquid system.
Gas and liquid chromatography systems often require the injection of unknown compounds into suitable eluding solvents. Prior methods of injecting liquid samples have employed septum injectors, plungers, and various sample injection valves having sample loops. All prior systems have encountered the problems of accurate measurement of the sample being injected as well as leakage problems associated with fluid systems under pressure. Also, prior injection devices tend to be cumbersome since they cannot be easily removed from the fluid system apparatus. It has been found that conventional syringes permit accurate gauging of the fluid samples being injected into a system. However, the problem of providing convenient access to the fluid system by the cannula without leakage problems usually associated therewith, still remains.